Various techniques have been used heretofore in obtaining an echo effect or reverberation in the tones generated by a musical instrument. In electronic organs and tone synthesizers of the analog type, echo effects have been produced by delay lines or by recording on endless tape loops using multiple read heads to reproduce the same tone at delayed intervals. Analog-type shift registers, sometimes referred to as "bucket brigade" devices (BBD), have also been used to generate multiple delayed tones which produce an echo effect. However, the BBD devices introduce undesirable bandwidth limitations which act to distort the echo tones.